摘要
A meandering riverbank plays a vital role in maintaining natural river ecosystems,providing habitats for riparian vegetation.However,dams have significantly altered riverbank shapes.To restore the riparian ecosystems,it is imperative to understand how different riverbank curvatures influence them.This study aims to uncover the ecological impacts of riverbank curvature on the structure and assembly process of plant communities in the riparian zone of the Yangtze River,regulated by the Three Gorges Dam(TGD)in China.We categorized the riparian zones into four types:cove,lobe,wavy and linear shapes.We documented the composition and diversity of riparian plant communities.Our findings revealed that wavy and cove riverbanks exhibited greater species diversity(with Shannon–Wiener diversity index values 1.5×higher)compared to communities along linear riverbanks.Furthermore,the analysis of functional traits indicated that wavy riverbanks promoted the differentiation of plant functional traits,thus enhancing ecosystem functions,with functional dispersion index(FDis)values 1.3 times higher than those of linear riverbanks.Significant variations in the assembly of riparian communities were also observed among different riverbanks,with standardized effect size(SES)values indicating a higher degree of niche differentiation in cove riverbanks(SES=0.4)compared to linear riverbanks(SES=–0.6).These results highlight the ecological importance of diverse riverbank curvatures in influencing the diversity,structure and assembly of riparian communities along the waterway.In summary,this study underscores the necessity of maintaining or restoring various natural morphological curvatures when rehabilitating riparian communities along rivers impacted by human activities.
蜿蜒曲折的河岸带为植被提供了栖息地,对维持自然河流生态系统具有重要作用。然而,大坝建设已经显著改变了河岸形态和河流生态系统。为了恢复河岸生态系统,了解不同的河岸弯曲度对河岸带植物群落的影响至关重要。本研究旨在揭示河岸弯曲度对长江三峡库区河岸带植物群落结构和构建过程的生态影响。本研究将河岸带分为4种类型:凹形、凸形、波浪形和直线形,通过野外调查获取河岸带植物群落的组成和多样性等数据。研究结果表明:(1)与直线形河岸带群落相比,波浪形和凹形河岸表现出更高的物种多样性(香农-维纳多样性指数值高出1.5倍);(2)波浪形河岸促进了植物功能性状的分化,从而增强了生态系统功能,其功能分散指数(FDis)值是直线形河岸的1.3倍;(3)不同河岸之间的河岸群落构建机制也存在显著差异,标准化效应值(SES)表明凹形河岸的生态位分化程度(SES=0.4)高于直线形河岸(SES=-0.6)。上述结果强调了不同的河岸弯曲度在影响河岸群落的多样性、结构和构建过程方面的重要性,意味着恢复河岸带植物群落时很有必要保持或恢复自然弯曲河岸。
基金
supported by the Comprehensive Ecological Restoration Survey of the Maqu Area in the Zoige Basin(Grant No.DD20243100)
Ecological Protection and Restoration Survey in the Dry Valley of the Upper Reaches of Minjiang River(Grant No.DD20220955)
Ecological Environment Survey and Ecological Restoration Technology Demonstration in Three Gorges Reservoir Decline Area(Chongqing Section)(Grant No.5000002021BF40001)
National Natural Science Foundation of China Supervisory Program(Grant No.42371071)
the Chongqing Municipal Bureau of Science and Technology,Doctor Through Train Project(Grant No.sl202100000390)
Chongqing Municipality Key Special Project for Technological Innovation and Application Development(Grant No.CSTB2023TIAD-KPX0077)
Tibet Shigatse City Science and Technology Plan Project(Grant No.RKZ2021KJ03).
